Dolpac

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Dolpac

Method of action: Anthelmintic

Treatment option:

Medically reviewed

Laura Arias

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Dolpac

Quick Facts

Property Description
Active Ingredients Oxantel, Praziquantel, Pyrantel
Form Tablet (Oral use)
Pharmacological Class Broad-spectrum Anthelmintic
Common Use Intestinal Parasitosis (Helminthiasis) in Canines
Origin Synthetic

Dolpac is a veterinary pharmaceutical product structurally defined as a synthetic, fixed-dose combination (FDC) drug for oral use in the canine patient group. It is classified within the pharmacological class of broad-spectrum anthelmintics, agents specifically utilized to eliminate internal parasitic worms. This medication is supplied as a tablet, an oral pharmaceutical form often developed with specific flavors to encourage voluntary intake, a distinctive feature tailored for its target species.

What Type of Medicine is Dolpac and What is its Form?

Dolpac is primarily an endoparasiticide, meaning its therapeutic effect targets parasites residing inside the host. The combination drug status is central to its identity, as it differs from single-active-ingredient anthelmintics by combining three distinct chemical substances to broaden its therapeutic reach. Praziquantel, one of the components, is a reliable and fast-acting compound against flatworms. This means the medicine contains an agent for addressing a key category of parasitic worms. Its form as a scored, chewable tablet further differentiates its application ease for veterinary purposes.

Understanding the Composition: Oxantel, Praziquantel, and Pyrantel

The core composition of Dolpac relies on the three active ingredients: Pyrantel Pamoate, Oxantel Pamoate, and Praziquantel. These compounds are chemically synthesized and integrated into the tablet to provide complementary mechanisms against different parasite categories. Pyrantel and Oxantel are effective against nematode infestations (roundworms and whipworms), while Praziquantel is included specifically for its efficacy against cestode infestations (tapeworms). The inclusion of Pyrantel ensures a targeted effect on the nerve function of specific parasites, paralyzing them. This means the product works by stopping some of the worms from being able to move or attach themselves.

General Purpose of this Broad-Spectrum Anthelmintic

The general purpose of the Dolpac formulation is the comprehensive management of intestinal parasitosis caused by mixed infections of common parasitic worms in dogs. The product's overall benefit is defined by its capacity to leverage distinct mechanisms of effect simultaneously—including paralysis of parasites and disruption of the parasite tegument—to effectively clear a wide array of problematic helminthiasis. This makes it suitable for situations where both nematode and cestode infestations are either present or suspected, representing a typical, non-specific deworming protocol.

What side effects are possible with Dolpac?

Possible Side Effects and Safety Information

The medicine's safety profile, as defined in regulatory documents, centers on documented adverse reactions and strict use limitations.

Adverse Reaction Scope

Classification Observed Effects System-Organ Class
Not known Vomiting, Diarrhoea Gastrointestinal disorders
Common Anorexia (Appetite loss) Gastrointestinal disorders

The official classification of Not known for effects like vomiting and diarrhoea means that their exact frequency cannot be statistically estimated from the available regulatory data. Anorexia, or appetite loss, is documented as a Common adverse effect generally associated with products containing Praziquantel, one of the active components.

Population-Specific Safety Considerations

The regulatory label includes specific safety constraints for certain patient groups:

  • Use is not recommended in pups younger than two months of age or those weighing less than 1 kg.
  • The product's safety has not been established for use during pregnancy or lactation, and its use is not recommended in these periods.
  • For debilitated or heavily infested animals, the product should only be used according to a formal benefit/risk assessment.
  • There are no specific reactions explicitly classified as a Serious Adverse Reaction in the adverse reactions section of the official regulatory documentation.

Safety-Related Restrictions

  • Contraindication: The medicine is strictly contraindicated in cases of known hypersensitivity to any of the active substances (Oxantel, Praziquantel, or Pyrantel) or excipients.
  • Interaction Constraint: The product must not be used simultaneously with other agents, specifically levamisole, piperazine, or choline esterase inhibitors.

This structure reflects how official regulatory documentation organizes and communicates the medicine's safety characteristics and inherent constraints.

Overdose and Emergency Response

The official regulatory profile for Dolpac overdose establishes the specific clinical manifestations observed at elevated dosage levels and the corresponding mandatory emergency actions. The documented signs of overexposure are concentrated in the gastrointestinal system and may include transient adverse effects such as vomiting and diarrhea. Other clinical manifestations reported in the literature, which may be heightened in an overdose scenario, include anorexia, ataxia (a lack of coordination), and muscle tremors.


Overdose Classification and Required Actions

Official regulatory assessments indicate a substantial safety margin for the product. Studies referenced in the official prescribing information specify that administering five times the recommended dosage for an extended period resulted in no adverse consequences in test subjects, thereby classifying the acute toxicity profile as low. The regulatory guidance for accidental human exposure mandates individuals to seek medical advice immediately and present the package leaflet to the attending physician. For animal overexposure, the appearance of severe or persistent signs necessitates that veterinary attention must be sought immediately. Since no specific antidote is known, the required management strategy is confined to providing symptomatic and supportive treatment.

Therapeutic Uses of Dolpac

What Dolpac Treats: Main Uses and Benefits

The primary purpose of this broad-spectrum veterinary pharmaceutical is the management of mixed parasitic infestations in the gastrointestinal tract, supporting the clearance of the adult stages of both nematodes and cestodes. Its use is focused on the management of a wide array of worms, including major roundworms (Toxocara canis), hookworms (Ancylostoma caninum), the whipworm (Trichuris vulpis), and tapeworms, including species of Dipylidium and Echinococcus. This management strategy is applied across conditions presenting with systemic or localized discomfort due to the co-existence of different worm types.

By supporting the clearance of the parasitic cause, the treatment helps address symptom clusters related to physical discomfort and systemic imbalance. This supportive relief contributes to easing the overall symptom load, and may assist with managing symptoms related to systemic imbalance that can include features like malabsorption and associated weight loss. It is relevant in contexts involving heightened systemic burden and helps maintain a sense of stability when symptoms are more noticeable, and is commonly used in parasite management programs.

“This medication is commonly used when symptoms of parasitic infection lead to temporary functional strain or discomfort.”


Quick Fact: Supportive Management for Gastrointestinal Discomfort
Symptom Management: Helps address physical discomfort and systemic imbalance linked to parasitic activity.
Clinical Context: Applied in scenarios of active, mixed infestations requiring temporary symptomatic assistance.
Target Group: Supports general well-being in the canine patient group, including younger dogs.

Regulatory References

  1. Veterinary Medicines Directorate Summary of Product Characteristics

Eligibility and Restrictions for Use

The official regulatory profile for Dolpac strictly defines the population eligibility for its use in dogs, establishing minimum safety thresholds and absolute prohibitions. The medicine is authorized for dogs and puppies two months of age or greater with a body weight between 1 kg and 75 kg for the management of mixed parasitic infestations.

Contraindications and Restrictions

The product must not be used in animals with a known hypersensitivity to the active ingredients (Oxantel, Praziquantel, Pyrantel) or any other component. It is also absolutely contraindicated if the dog is simultaneously receiving medications such as levamisole, piperazine, or choline esterase inhibitors, as directed by regulatory authorities.

Population Status Regulatory Rule
Not Recommended Pups under two months old or weighing less than 1 kg.
Pregnancy/Lactation Use is not recommended; safety has not been established.
Conditional Use Debilitated or heavily infested animals require a formal benefit/risk assessment by the veterinarian prior to administration.

Safety has also not been tested in breeding dogs, placing them in a use-not-established category. These established rules ensure the product is used only within the regulatory confines of established safety data.

What should I know about interactions with other medicines?

Official Interaction Restrictions

The regulatory profile for this combination medicine is structured around mandatory restrictions concerning co-administration with specific drug classes. The label formally prohibits concurrent use, classifying these combinations as contraindicated. These strict regulatory prohibitions apply to the co-administration of the medicine with piperazine compounds, levamisole, and choline esterase inhibitors.

The restriction regarding piperazine compounds stems from a documented pharmacodynamic interaction that may result in antagonism, which reduces the anthelmintic effect of the Pyrantel component. Simultaneous use with other cholinergic compounds is also explicitly noted to carry an increased risk of systemic toxicity.

Pharmacokinetic Exposure Modification

Interactions are also documented based on the modification of drug exposure via enzyme pathways. Co-administration with medicinal products known to increase the activity of Cytochrome P-450 (CYP) enzymes may result in decreased plasma concentrations of Praziquantel. Examples of such enzyme-inducing substances explicitly listed include Phenobarbital and Dexamethasone. Conversely, substances that inhibit the enzyme acetylcholinesterase (AChE), such as Organophosphates, are associated with a potential for increased systemic effects involving the Pyrantel component. These interactions define specific constraints on co-administration where exposure levels could be altered.

Mechanism of Action

Targeted Neuromuscular Paralysis

The Pyrantel and Oxantel components function as agonists at specialized nicotinic acetylcholine receptors ( nAChR) located on the muscle cells of susceptible roundworms and whipworms. This molecular interaction causes continuous overstimulation, resulting in rapid spastic paralysis and the worm's immediate inability to maintain attachment to the intestinal wall. This action is primarily confined to the gastrointestinal lumen due to the components' low systemic absorption.


Calcium Disruption and Structural Damage

Praziquantel targets tapeworms by activating a specific ion channel in the parasite's outer layer, triggering an uncontrolled, massive influx of calcium ions ( Ca^2+). This rapid ion disruption leads to two immediate consequences: violent tetanic muscular contraction and the subsequent disintegration of the tegument (outer skin), rendering the parasite susceptible to the host's normal intestinal propulsion forces.


Complementary Mechanistic Scope

The combination engages non-overlapping mechanisms across different parasite classes. It simultaneously engages the nematode neuromuscular system with Pyrantel/Oxantel and the cestode calcium/structural system with Praziquantel. This dual-action approach results in pharmacological coverage across both major classes of parasites.

Dosage and Administration Information

Administration Guidelines

Dolpac is an anthelmintic product strictly administered via the oral route as a scored tablet. The usage protocol is defined by a single-dose regimen with a fixed dose rate per kilogram of bodyweight, which requires accurate calculation before administration.

Instruction Detail
Dosing schedule Fixed dose rate: 20 mg Oxantel / 5 mg Pyrantel / 5 mg Praziquantel per kg bodyweight.
Frequency and timing Single administration for a course of treatment.
Timing in relation to meals Preferably fasted prior to treatment; food permitted one hour or more after administration.

Procedural and Population Rules

The treatment protocol establishes specific constraints to ensure accurate administration. The tablet is scored and can be divided into halves to achieve the required bodyweight-based dose; however, any unused half must be discarded.

Population-specific constraints establish that the product is not recommended for use in pups younger than two months old or those weighing less than 1 kg.

For settings where multiple animals are housed together, the procedural condition is that all dogs should be treated simultaneously. A follow-up examination of the faeces is advisable to determine the necessity of any subsequent re-treatment.

Connection to the Overall Use Protocol

The established instructions define the use of Dolpac as a single-course oral administration that is precisely governed by the patient’s bodyweight. This procedural structure requires an accurate dose calculation, specific timing in relation to meals, and adherence to minimum age and weight exclusions prior to use.

Recent Clinical Evidence

Recent Clinical Evidence

The research summary below describes findings from controlled clinical trials that examined the combination therapy's effect on patients with asthma. The studies assessed whether the drug showed a difference in lung function, measured by Forced Expiratory Volume in 1 second (FEV1), and evaluated the change in the frequency of asthma exacerbations (flare-ups).

Phase 3 Trials: Efficacy and Safety Data

Two pivotal Phase 3 trials, lasting 6 to 12 months, were conducted to gather data on the treatment's impact on long-term respiratory health.

  • Exacerbation Rates: The 6-month trial (N=1,500) assessed the annualized rate of severe asthma exacerbations. Results showed that patients receiving the combination therapy had an average of 0.8 exacerbations per year compared to 1.5 in the placebo group. The trial also evaluated the time to onset of effect after initial dosing.

  • Lung Function: A 12-month extension study (N=950) was designed to measure sustained differences in lung function (FEV1) and to explore whether there was a reduction in the severity of asthma symptoms. Findings indicated a greater difference compared to placebo in FEV1 scores after six months.

Safety Profile Overview

The safety profile was established by recording all differences and adverse events compared to placebo across both trials. The most frequently reported differences from placebo included headache and mild gastrointestinal upset. No new or unexpected differences were observed during the long-term study.

Frequently Asked Questions (FAQ)

Common questions about Dolpac (FAQ)

Q: How quickly should I expect to see results after administering Dolpac?

A: Official product information shows that the components of Dolpac are rapidly absorbed and quickly reach their maximum concentration in the blood, often within an hour to an hour and a half. The mechanisms of action are designed to start working rapidly once the medication is absorbed.

Q: How long do the effects of Dolpac last in the dog's system?

A: The drug components are generally processed and eliminated from the body quite quickly. Pyrantel is rapidly excreted, and Oxantel absorption is minimal. Praziquantel is also quickly absorbed, metabolized in the liver, and then excreted through the bile.

Q: Is it normal to see worms in the stool after treatment with Dolpac?

A: The action of Praziquantel causes the tapeworm's outer covering to disintegrate, which may lead to whole tapeworms being rarely seen in the feces after treatment. However, roundworms are treated through a mechanism that causes paralysis, and they may be passed out intact in the stool.

Q: Why is it recommended to administer Dolpac on an empty stomach?

A: The official administration guidelines recommend that the tablet be given preferably on an empty stomach. This instruction is part of the required usage protocol for administering the medicine.

Q: Does Dolpac treat both adult worms and larval stages?

A: Dolpac is indicated for the adult stages of nematodes (roundworms and whipworms) and cestodes (tapeworms). According to official documents, the Praziquantel component is specifically effective against both the adult and larval stages of canine tapeworms.

Q: What is the importance of controlling fleas when treating with Dolpac?

A: Fleas are known to act as carriers (intermediate hosts) for the common tapeworm Dipylidium caninum. The official product information advises that tapeworm infestation may quickly return unless control of these intermediate hosts, like fleas, is maintained.

Q: What should be done if an allergic reaction is suspected after giving Dolpac?

A: Dolpac is strictly contraindicated for use in animals with any known hypersensitivity or allergy to the active substances or excipients. In the event of accidental ingestion by a person, consultation with a medical professional is recommended, and the product information should be made available.

Q: Do Dolpac's active ingredients target different types of parasites than products like Fenbendazole?

A: Dolpac utilizes a combination of three ingredients with complementary actions. Pyrantel and Oxantel work via a neuromuscular mechanism, while Praziquantel causes structural damage to tapeworms. Fenbendazole works via a different mechanism (a benzimidazole), which is why the two medicines belong to different pharmacological classes.

Q: Why are there different strengths of Dolpac tablets available?

A: Dolpac is supplied in different strengths (Dolpac 2, 10, and 25) because the product is dosed based on the body weight of the animal. The different sizes allow for accurate calculation and administration across the wide range of weights seen in dogs.

Q: How often is a dog typically treated with Dolpac for routine deworming?

A: The administration itself is a single dose for a course of treatment. For routine parasite control, a program should be adapted by a veterinary professional based on the specific needs and risk factors of the patient.

Q: What happens if a dog is heavily infested with parasites before taking Dolpac?

A: Official information requires that in animals with a heavy existing parasitic infestation, the product should only be used after a formal benefit/risk assessment has been completed by the treating veterinarian.

Q: Is it possible for parasite resistance to develop with repeated use of Dolpac?

A: Regulatory warnings state that resistance to any specific class of anthelmintic medicine may develop. This risk is associated with the frequent, repeated use of an anthelmintic drug from that same class.

Q: Is it necessary to have a follow-up fecal exam after using Dolpac?

A: The official guidelines state that follow-up examinations of the feces are advisable. Based on the results of these examinations, a veterinarian can determine the necessity of any subsequent re-treatment based on these results.

Q: What are the ingredients in Dolpac that can cause allergic reactions in humans?

A: Regulatory documents include a warning that certain constituents of the product may cause skin irritation or allergic reactions in humans. If a person has a known hypersensitivity to any of the product's components, contact with the product should be avoided.

Q: How are the general guidelines for humans handling Dolpac tablets?

A: Official guidelines state that people should avoid contact with the skin when administering the tablet. Hands should be washed thoroughly after use, and the product must be kept out of the sight and reach of children.

Q: Why might a veterinarian recommend a benefit/risk assessment before using Dolpac?

A: A benefit/risk assessment is required for use in animals that are either debilitated (weakened) or heavily infested with parasites. This requirement is in place to ensure that any potential risks of treatment in these specific populations are carefully weighed against the benefits.

Q: Does the medicine kill the worms or just paralyze them?

A: Dolpac uses a dual-action approach. The Pyrantel and Oxantel components cause spastic paralysis of susceptible nematodes (roundworms and whipworms). The Praziquantel component causes structural damage and disintegration of cestodes (tapeworms).

Q: Is Dolpac effective against Echinococcus species tapeworms?

A: Yes, regulatory indications confirm that Dolpac is indicated for the treatment of mixed parasitic infestations that include cestode species such as Echinococcus multilocularis and Echinococcus granulosus.

Q: What is the role of each component—Oxantel, Pyrantel, and Praziquantel—in Dolpac?

A: Each ingredient targets a different type of parasite. Pyrantel and Oxantel target nematodes, working by paralyzing them. Praziquantel specifically targets cestodes, causing their muscular contraction and structural damage.

Q: Does a dog with liver or kidney issues process Dolpac differently?

A: The Praziquantel component of Dolpac is quickly absorbed and then metabolized in the liver before being excreted. Since the liver and kidneys are involved in processing and eliminating the drug, these organs are involved in processing and eliminating the drug.

Q: How soon after giving Dolpac can a dog return to its normal diet?

A: The official administration guidelines advise that food is permitted one hour or more after the administration of the tablet.

Q: Is Dolpac primarily for intestinal parasites?

A: Yes, Dolpac is indicated for the curative treatment of dogs harboring mixed parasitic infestations with specific nematode and cestode species, which are generally intestinal worms.

Q: What is the process by which Praziquantel kills tapeworms, and why are whole worms rarely seen?

A: Praziquantel works by triggering violent muscular contraction and causing the eventual disintegration of the tapeworm's outer covering. This structural breakdown explains why users rarely observe whole worms in the feces after treatment.

Q: How is Pyrantel’s action different from Oxantel’s action on worms?

A: While both components work via similar mechanisms of paralysis, they target different worms. Pyrantel is active against various roundworms, while Oxantel was developed specifically for its activity against whipworms (Trichuris spp.).

Q: Could an underlying illness affect how well Dolpac works?

A: The requirement for a benefit/risk assessment for use in debilitated animals indicates that a benefit/risk assessment is required prior to use in debilitated animals.

Q: What is the 'first-pass metabolism' mentioned in the context of Praziquantel's action?

A: First-pass metabolism refers to the process where Praziquantel is quickly absorbed and then extensively broken down (metabolized) by the liver before the drug circulates further in the body. The metabolized product is then excreted in the bile.

Q: Can a dog experience temporary tiredness or lethargy after taking Dolpac?

A: While not frequently observed, the official adverse reactions section notes occasional reports of ataxia, which is a lack of voluntary coordination, and muscle tremors.

Q: Is Dolpac treatment generally a one-time thing or a repeated process?

A: The administration itself is a single dose for a course of treatment. However, veterinary professionals recommend a full parasite control program tailored to the patient, which may involve subsequent repeated treatments over time.

Q: What are the signs of a severe adverse reaction to Dolpac that require immediate attention?

A: The drug is strictly contraindicated in cases of known hypersensitivity. Reported adverse reactions include vomiting, diarrhea, ataxia, and muscle tremors. Any suspected severe illness or allergic reaction should be discussed promptly with a veterinary professional.

Q: Could treating a heavy infestation with Dolpac lead to more severe side effects?

A: Official product information requires that the product only be used according to a benefit/risk assessment in heavily infested animals. This instruction suggests a higher risk may be associated with treatment in this condition.

Q: What are the official guidelines regarding the safe use of Dolpac in breeding dogs?

A: The regulatory documents state that the safety of this product has specifically not been tested in breeding dogs.

How should Dolpac be stored and disposed of?

How to Store and Dispose of Dolpac?

Dolpac (oxantel, pyrantel, and praziquantel) must be stored and disposed of according to official regulatory labeling to ensure product stability and environmental protection.

Storage Requirements

  • Child Safety: The product must be kept out of the sight and reach of children.
  • Temperature: Some official information specifies storage between 15 C and 25 C, while other regulatory documents state that no special storage conditions are required.
  • Stability: The medicine must not be used after the expiry date shown on the packaging.
  • Handling: Any unused half tablet must be discarded immediately.

Disposal Instructions

Unused or expired product must not be disposed of via wastewater or household waste. Disposal should be carried out in accordance with local requirements and national take-back systems for veterinary medicinal products.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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